In a data storage system having a plurality of clusters, each cluster configured to store data, logical volume data written to one cluster may optionally replicated to one or more peer clusters of the data storage system. For users that demand short recovery times to access the data, copies tend to be made to all clusters in a common grid. From a cluster data capacity perspective, all clusters typically need the same storage capacity in order to absorb new user data as well as absorb all replicas of data written at peer clusters.
A cluster may come in different forms, for example, a “disk-only” solution configured to store data with short recovery time to access data, and a “complete” solution configured to both store data with a short recovery time to access data, such as disk and solid state disk, and to store data with high capacity and longer recovery time to access data, such as a data storage library. Data may be migrated and archived from the short recovery time storage to the library. Because of the different characteristics of the clusters, it is typically required that all the clusters in a grid data storage system be of the same type.